One of the chief causes for the failure of retinal detachment surgery is the development of massive vitreous retraction (MVR) or massive periretinal proliferation (MPP). Only about one in three of eyes afflicted with MPP responds favorably to modern vitrectomy techniques in the hands of the best surgeons. In eyes which are not successfully treated, even ambulatory vision is not maintained. Thus there is a need for better understanding of and more effective treatment of MPP. Based on promising clinical observations in rabbits, we plan to develop a reproducible model in this same animal. The main objective in developing this model is to delineate the natural history and pathogenesis of MPP. Light microscopy will be used to monitor the development of MPP and to confirm that a reasonable model has been developed.